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Remove it and prove it: Better cleaning through scientific validation

September 19, 2010
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Cleaning is the removal of unwanted matter, including macro soil we can see, such as dirt, debris and spills, as well as micro soil, such as harmful bacteria, viruses, spores, dust particles and chemical substances below the threshold of human perception.

Micro soils, with their ability to enter the human body, often have a major impact on health and require critical emphasis during cleaning.

How do you know when you have effectively removed these micro soils that can endanger human health?

In a word: Measurement.

New tools in the toolbox
The following is an overview of three types of devices that can help validate a hygienic cleaning program.

For example, ATP testers determine the presence of adenosine triphosphate, which is present in organic matter to determine overall bio-soiling.

Biodetectors determine or utilize the presence of antibodies, enzymes, DNA, and other components of particular living organisms.

And mold detectors detect fungal enzymes as indicators of the presence of mold.

ATP devices
ATP is the most widely recognized and accessible marker since it enables the broadest assessment of the presence of organic soils.

According to Hygiena, a manufacturer of ATP testing devices: “ATP (adenosine triphosphate) is present in organic material and is the universal unit (or currency) of energy used in all living cells.

“ATP is produced and/or broken down in metabolic processes in all living systems. Processes, such as photosynthesis in plants, muscle contraction in humans, respiration in fungi, and fermentation in yeast are all driven by ATP.

“Therefore, most foods and microbial cells will contain some level of naturally occurring ATP. The ATP device uses bioluminescence to detect residual ATP as an indicator of surface cleanliness.

“The presence of ATP on a surface indicates the presence of contamination, including food residue, allergens and/or bacteria, and potential for the surface to support bacterial growth.”

ATP results are inconsistent, however, when testing surfaces of organic nature (e.g., unfinished wood) because those surfaces have innate levels of ATP.

“Background ATP levels can vary among building materials,” says Dr. Gene Cole, professor of environmental health sciences at Brigham Young University. “Thus, the method must be researched according to a specific cleaning approach, the materials and surfaces to be cleaned, and the desired outcome, in order to enhance interpretation.”

Tiled restrooms, stainless steel and tiled food service areas, and laminated desktops, are ideal since they have no inherent ATP.

According to Dr. Robert W. Powitz, who holds a master’s in public health with a specialty in institutional practice and a Ph.D. in environmental health from the University of Minnesota, “The more I use ATP testing in my work, and the more I explain its operational capabilities and limitations to my clients, the greater is our collective level of comfort in using it to define and set reasonable guidelines and standards for cleanliness.”

ATP-based and/or Petri film-based cleaning protocols are currently in development by several industry consultants and KaiScience, which is supported by Kaivac Inc. These cleaning protocols will include: 1. Flat Surface Cleaning (FSC) (Above Floor); Hard Floor Cleaning (HFC); and Uneven Surface Cleaning (USC) (Above Floor).

FSC, HFC and USC protocols all show significant after-cleaning reductions in contamination compared to traditional methods.

Other protocol data are being gathered.

Hand-held ATP meters enable on-site results monitoring within minutes of the completion of cleaning, and provide a more effective way to assess cleanliness than visual inspection.

Hospital Infection magazine stated in 2000: “A four-part study assessing cleanliness on up to 113 environmental surfaces in an operating theatre and a hospital ward was reported.

“Surfaces were assessed visually, using microbiological methods and ATP bioluminescence. … Using published microbiological and ATP specifications, 70 percent and 76 percent of sites were unacceptable after cleaning. Visual assessment was a poor indicator of cleaning efficacy with only 18 percent considered unacceptable.”

Additionally, Professor Mike Wren, biomedical scientist in clinical microbiology at University College London Hospital, said, “Some of the most useful indicators of true cleanliness are ATP bioluminescence measurements.”

Biodetectors can detect specific germs, allergens and other organisms using “biological recognition.”

These units range in size from desktop-sized to hand-held, and use a variety of collection methods.

The devices can use antibodies, living bacteria, single-celled organisms or tissues of higher organisms to detect the presence of unwanted substances based on a biological reaction.

For example, if living cells inserted in the device react to certain antibodies, the biodetector can identify the specific bio-contaminant.

Results can be delivered within 30 to 90 minutes.

Biodetectors, originally developed to thwart bioterrorism, may prove useful to the cleaning industry.

These fall into three categories: Those detecting a DNA sequence or protein that identifies the contaminant; living cells that react to specific agents and produce a measurable response; and mass spectrometry units that identify chemical components by molecular mass and cross-match them with biological agents of known molecular mass.

Portable DNA detection devices can now prepare and test samples within a very short time.

In some cases, the units basically break open bacterial spores and extract their DNA to identify the organism like a virtual “laboratory on a microchip.”

Procedures that used to take six hours in a lab can now be done in the field in perhaps an hour or less.

Northwestern University has developed a DNA-based biochip for identifying pathogenic microorganisms.

Other units are being designed for anthrax identification.

The Autonomous Pathogen Detection System, or APDS, monitors air like a smoke detector and can detect and identify bacteria, viruses and toxic substances.

Costs and expertise required for most of these devices remain prohibitive for cleaning validation purposes — they were mainly designed for the military and medical sectors — but prices are expected to fall, and ease-of-use will improve as demand grows and biodetector technology advances.

Mold detectors
Mold detectors are hand-held portable devices that detect fungal enzymes to determine total fungal biomass.

Though the units cannot differentiate between types of mold, they can accurately determine on-site, within one hour, the presence of fungi and the effectiveness of mold remediation on surfaces including wood, grout and various building materials.

“Our experience with (a mold detector) as the final clearance methodology for HVAC and mold remediation has been excellent. It documents the efforts of our technicians,” says Tim Herbert of Air Purification Specialists Inc.

Mold detectors and test kits can be initially costly ($7,000-plus each), but are especially useful for mold remediation verification and can recoup costs over time.

According to Gene Cole, “Comparative research is necessary to identify optimum cleaning effectiveness measurement methods for specific target markers across different environments, materials, surfaces and applications.

“Such research, conducted in a cooperative mode, will serve to define the many aspects of clean, and will help to establish consensus standards of care for cleaning effectiveness within the industry.”

In short, science now provides us with technology-assisted eyesight to detect generally invisible micro soil, then remove it and prove it.
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